Configuration Design And Theory Of Ultra-short Double-layer Energy-Absorbing Structure With Synchronous Collision Collapsing

The issue of safety of micro-electric vehicles with important significance for energy saving and environmental protection and improving space utilization of passenger vehicles needs to be urgently solved.This paper combines the research status of thin-wall energy-absorbing structures of traditional vehicle energy-absorbing structures.The configuration has designed a welded double-layer energy-absorbing structure suitable for the ultra-short crumple stroke of the installation space of a miniature electric vehicle.Based on this,a motorized chassis structure of a micro motor-driven vehicle driven by a hub motor was explored.(1)The research focuses on the low-speed segment of the existing vehicle collision absorption structure.In order to make its performance optimizing design meet the requirement of C-NACP,For the three common thin-walled structures and materials,using SolidWorks to model and import LS-DYNA,taking the energy absorption efficiency and peak stress as the evaluation index and using orthogonal test to load 50 km/h,conducts a simulation optimization analysis.At the same time,the orthogonal design method and the comprehensive test method are used to optimize the four structural parameters.The result shows that energy-absorbing properties are impacted by wall thickness and length significantly.The aluminum alloy thin-walled rectangular tube,which has the highest energy-absorbing efficiency and the lowest peak stress,is the most suitable one used as the automobile energy-absorbing box.Its optimal length is 180 mm and the optimal thickness is 3 mm.(2)Configuration design a kind of the combination of Q420 and aluminum alloy welding double-layer synchronous crumple thin-wall rectangular tubular energyabsorbing structure,applies SolidWorks to modeling and imports LS-DYNA software to use orthogonal test method in marshalling simulation test and analysis of significant structural parameters.And further using the least square method,the theory formula of the energy absorption efficiency about the significant structural parameters of welded double-layer thin-walled rectangular tube is deduced.The results show that when the energy absorption efficiency of the structure is 85%,the length of the structure is only about half of the traditional single layer structure.The wall thickness of inner and outer layers and length are the two factors which impact energy-absorbing efficiency significantly.The theoretical solution of significant structural parameter equation and structural comprehensive simulation verification,the absolute error can be less than 5% in a certain range.The theoretical solution of the equation has obvious effectiveness.(3)Using a miniature car as a reference,combined with dynamic performance parameters,a stepped collapse deformation motorized chassis structure was designed.The cruising range can reach more than 200 km,the maximum speed can reach 90km/h,and the crash simulation process results show that: The energy efficiency is up to 95%,the peak force is reduced by 10%,and the acceleration peak value lower than the standard requirement of 50 g,which is of great significance for the design and development of miniature electric vehicle products.